ML19317G027
| ML19317G027 | |
| Person / Time | |
|---|---|
| Site: | Rancho Seco |
| Issue date: | 05/12/1979 |
| From: | Mattimoe J SACRAMENTO MUNICIPAL UTILITY DISTRICT |
| To: | |
| References | |
| NUDOCS 8002210730 | |
| Download: ML19317G027 (3) | |
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SACRAMENTO MUNICIPAL UTILITY DISTRICT
' 'G201 S Street. Box 15830. Sacramento. California 95813: p)na 452 3211
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- uc1:ar acquiatory Cca.:ission -
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1 1990 morth Califcrnia coulevard t
Jalnut Creek.- California N 596 j
i Attentiori: - i!r. _il.. ii. Engelxen..jirector l
sear. '-:r. Engeli:en:
Rancho Seco Guclear Generatino Station Unit 'l Dockat Ho. 50-312 g-As a follou uo to the vistrict's telennone discussig.5 e Anril _29 and 33,1975 s.ith ressrs. Johnson and Uch.ros of p +r n?fi<
we 4re subnitting a renort on a nrobler er.countereo ui d tue ca ctor
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building polar cranc.
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On' acproxin3tely February h', 1974, during a...m.
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. inspection of the containr:ent building poler crane, sn of.:4 'ccite u.11ch connect the crane and ties to tise rain cirders re fe:md tn l-loose. Tais was reported on..cnconferminn ::e5crt ao. tw3...
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- riisr.ositioning toc.:oncorforcing fleport, t.he lccatel Pcuar Corrora tice verbally _ rer.orted ti:e problera to tnc Harnischfegcr Corneration. rm i
' crane designcr and manufacturer.
It was agree i that thc existica U
ASTil A-325-isolts should be replaced with A-430 bolts to iner. sap. t.c '
strenoth of.the connection.
harnischfcoer was to investicati ti.e rroblem and. report its findinos.
. l Researcning tne problaa further, Cechtal discovered t: at L.-
design of the _cnd ties and the bo_lting connecting them to tna train
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- girders-did not. conform to the original design calculations.
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.orioinal calculations showed a need for a vertical restraint or " tic-
.dod" to provide acceptaoic stability during a seismic event. The calculations were amended curing the initial review crecess to acd a 4-.
seisaic, brace _or buaper to preve'nt-thc crane fror.i comina.'off tii: sur-cart steel.
Heuever, theLcalculations received by bechtel did not reflect tne effect of the elimination of the fixed restraint and tk 1-design of tne end' ties furnished.
In snite of both.:ritten and ver: 1 Lcortunication with.harnischfcger, we could not get a titely response explaining lthediscrenancy.
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-T-f*ay 12, 1975 Follouing the initial replaconnt of tne bolts,-their con-diticn tas carefull / conitored and the problem reoccurred.
It_uas also j
oiscovcred that there was an intent.ittent iaterference Lctucen t:m run-uay.surcorL steel and t.ie scis.ic brace. Uistence of tha intcrfcrer.cc uas dependent.on tna relative ocsition of ::.e crane on the rail (1-1/4" lateral covement nossibleb This iaterference uas eliminated by a
'rachining the restraint shoe.
It is-not known at this 1tir.'e whether the l-boltiloosening uas due to ncr.ral operating stresses or taa interference.
e Cur inability to obtain a satisfactory response fron liarniscafcger and the need to correct'any pctential crobicm crior to fuel loadino en-couracec us'to have Lechtel cerfora a detailed analysis of the ena ties cnd their connections.to tne oirders. This analysis shoucd a need for greater joint capacity to resist the simultaneous arnlication of vertical
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and horizontal scismic loacs, i!cvisions 2 and 3 of JCa Co. f W were eritten to provide for rcodifications.to uring tie stresses witnir clicuabic #
limits.
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He directed Bechtel to proceed uith the work and at the s me time foruarded details of the proposed chances to harnischfe::er for its A
'revice and approval.
In its response, Harnischfeger indicated that the 1
uork was not reouired but did not orovide any technical suonort for its
~D position. L Ue croceeded with the work and coholated it orior te fuel
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Since that tirc.e there have been several <.eetinc;s ana nuocrous
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letters between'S:iU),. Cechtel, and harniscafeger, all aircca at reachina -
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acrecrent-on the assumptions used in ana19zino end tic stresscs durino '
c scismic cveat. Also, in Septether anc Octo!cr, it74, Harnischfccer
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'did revicu and accept the Gechtel redesign uhile still raintainino its.
-position that the codification t.ork ras not required.
On' April 14,1975,-ec roccived the final calculations fron Harnischfeger conpletely reanalyzing the as-shippeo cranc girdcr-enu tie. configuration.. Prior to recciot of,tDese calculations,-it nati bacn
!!arniscafoger.'s.rosition that the as-shipped crane complied uith th-design rcoutrements. These calculations shou that the_ crana stability
,uas acceptable; however, the end-tic bolting wcs overstr._ssac.
. Althouc;h the procurercent specifications and FSaR clearly state that thclcrano is to.be designed for siuultaneous anrlication of vertical
-and horizontallseismic loacs, Larnisci.feger still feels that the renuirc-ment;is unduly severe. There may bc sote valiuity to.this 'positioin
.i;ouever. the requirar.ent-is'one to waich uc cc:xitted ourselves and with
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-uhich.se'are in conpliance, c
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- r. I'. ).. Utg'.ll;cn ::ay 12. 1975 If t.c can rrovide an / additicaal inferration, please Co r.ct Scsitate to contact us.
Sincercly ycars.
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